As computer technology blooms, electronic components such as central processing units (CPUs) of computers are made to provide faster operational speed and greater functional capabilities, which results in the CPUs generating a significant amount of heat. It is desirable to dissipate the generated heat quickly, for example, by using a heat sink attached to the CPU in enclosures. Generally, a locking device is required for mounting the heat sink to the CPU.
In the earlier time, a heat sink is mounted to a CPU via bolts which extend through a mounting section of the heat sink to engage with a printed circuit board on which the CPU is mounted. However, using of bolts to install or remove the heat sink is complicated and time-consuming.
Nowadays, a heat sink is often securely placed on a CPU mounted on a socket via a plate-type clamp which comprises a pressing portion crossing through and resting on the heat sink and a pair of locking legs formed at opposite ends of the pressing portion to engage with catches of the socket. Unfortunately, the plate-type clamp which generally has a great width occupies space of the heat sink which is originally desired to form more heat-dissipating fins for the heat sink. The clamp thus obviously reduces the heat dissipating surface area of the heat sink when sacrificing these desired fins and therefore decreases the heat dissipating efficiency of the heat sink. Furthermore, when mounting the plate-type clamp to the heat sink, it is difficult to maintain the clamp exerting a balance force on the heat sink and the plate-type clamp is easy to accidentally move when subject to libration. So the stability between the heat sink and the plate-type clamp is poor, and plate-type clamp is easy to loose.